AI car problem

After collision AI cars that beacme reversed are approaching to the next way point in reverse direction itself…

How can i resolve this???

sounds like you are telling your car AI to follow next waypoint in forward position of local axis of car.
Try using global axis
Or number your waypoints trough an array and use waypoint++ to tell your AI car to follow next waypoint in a row properly
also you can try cheating your own code, for example, if car has been turned by more than n degrees, then destroy/respawn car at same position with proper angle… kind of what most racing games do, when you turn your car on roof